E.H. Reck, 2001 .“Clarifying the nature of the infinite”: the development of metamathematics and proof theory(页面存档备份,存于互联网档案馆). Carnegie-Mellon Technical
discussing the relationship between truth values in intuitionistic logic and topos theory on the one hand and classical logic on the other. 逻辑连结词 真值表 真值函数